Age difference of human nail components and morphology.

Hirose, Takashi; Momota, Hitoshi; Kitajima, Takayuki; Okura, Sayuri; Matsuda, Toshiko; Motoyoshi, Katsuhiro

doi:10.5107/sccj.24.98

Cited by 4 publications

(4 citation statements)

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“…Lipid distribution in the nail plate The lipid content in the human nail plate was found to be much lower than that in the stratum corneum of skin ). However, various lipids such as long-chain fatty acids, free fats, cholesterol, squalene and phospholipids are present in the human nail plate (Spearman 1978;Hirose et al 1990). It is thought that the lipid distribution and concentration in the human nail plate may affect the drug permeation, particularly the partition of drugs into the membrane.…”

Section: Resultsmentioning

confidence: 99%

Drug Permeation through the Three Layers of the Human Nail Plate

Kobayashi

Miyamoto

Sugibayashi

et al. 1999

Journal of Pharmacy and Pharmacology

117

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The in-vitro permeation characteristics of a water soluble model drug, 5-fluorouracil, and a poorly water soluble model drug, flurbiprofen, were investigated through three layers of the human nail plate (namely, the dorsal, intermediate and ventral nail plates), using a modified side-by-side diffusion cell. The dorsal-filed nail plate, the ventral-filed nail plate and the dorsal-and-ventral-filed nail plate were prepared to known thicknesses and then used with the full-thickness nail plate to investigate the permeation characteristics of each single layer. Most of the lipids in the human nail plate were found in the dorsal and ventral layers. The rank orders of the permeation fluxes for 5-fluorouracil and flurbiprofen were both: dorsal-and-ventral-filed nail plate > dorsal-filed nail plate > ventral-filed nail plate > full-thickness nail plate. With respect to 5-fluorouracil permeation through each single layer, the permeability coefficient of the intermediate layer was higher than those of other single layers. However in the case of flurbiprofen, the permeability coefficient of the ventral layer was higher than other single layers. The diffusion coefficients of 5-fluorouracil and flurbiprofen in the dorsal layer were the lowest of any single layer. The drug concentration in each layer was estimated using each respective permeation parameter. The drug concentration in the nail plate was observed to be dependent on the solubility and the flux of the drug. From these findings, we suggest that the human nail plate behaves like a hydrophilic gel membrane rather than a lipophilic partition membrane and that the upper layer functions as the main nail barrier to drug permeation through its low diffusivity against the drugs.

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Section: Resultsmentioning

confidence: 99%

Drug Permeation through the Three Layers of the Human Nail Plate

Kobayashi

Miyamoto

Sugibayashi

et al. 1999

Journal of Pharmacy and Pharmacology

117

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“…In recent years, there has been increasing consciousness about maintaining the nails in good condition due to the popularity of beautiful nails. [2][3][4] Maintaining optimum water levels in the nail plate is very important since m oisture levels vary with ambient con-ditions (temperature and relative humidity). The water content of human nails is reported to be 7-25% (dr y and wet basis, depending on references) under living environmental conditions.…”

Section: Introductionmentioning

confidence: 99%

Determining Water Content in Human Nails with a Portable Near-Infrared Spectrometer

Egawa

Fukuhara²,

Takahashi³

et al. 2003

Appl Spectrosc

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The water content of human nail plates was determined using a portable near-infrared (NIR) spectrometer with an InGaAs photodiode array detector. NIR diffuse reflectance (DR) spectra were collected from 108 cut nail plates with different relative humidity and in vivo from fingernails. Partial least-squares (PLS) regression was applied to the NIR spectra in the 1115-1645 nm region to develop calibration models that determine the water content in the cut nail plates and fingernails. A good correlation was obtained between the NIR spectra and the water content measured by nuclear magnetic resonance (NMR) for the NIR measurement of both cut nail plates and fingernails. The results indicate that the water content in the nails can be determined very rapidly (1 s) by means of the portable NIR spectrometer and PLS regression.

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“…As suggested by the in vitro studies reported by Sugawara et al (6–8), the low water content and weak mechanical strength of the nail plate are considered as causes of split nails. Hirose et al (4) reported that water uptake of the nail plate was related to its lipid content. This suggests that the difference in the amount or composition of lipids may be one cause for the difference in the water content and water retention.…”

Section: Discussionmentioning

confidence: 99%

“…The nail plate is composed mainly of hard keratin and lipids, like hair. It was reported that the total lipid content in the nail plate was 1.4% (3), and that its fatty acid content was higher and ceramide content was lower than the stratum corneum (4). As there has been interest in maintaining the nail in good condition these days, maintenance of optimum water level of the nail plate is very important since water content varies with ambient conditions such as temperature and relative humidity (5).…”

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confidence: 99%